Harmless. It is large and boldly marked, which frightens people, but it has no medically significant venom and stays in its web. A bite would be comparable to a bee sting and is very hard to provoke.
SizeFemale 19–28 mm body; males are around a quarter of that
MarkingsBright yellow and black abdomen with an almost enamelled look · A thick white zig-zag of silk down the middle of the web
WhereSunny gardens, tall grass, hedgerows and the edges of fields — anywhere with stems strong enough to anchor a big web.
SeasonFemales reach full size in late summer, which is when people notice them
How to tell it apart
Bright yellow and black abdomen with an almost enamelled look
A thick white zig-zag of silk down the middle of the web
Sits head-down at the centre with legs paired, making an X shape
Legs black with orange or reddish bands near the body
Large circular orb web, usually chest to head height in vegetation
Where you’ll find it
Across almost all of the contiguous United States, plus southern Canada and into Mexico. If you are anywhere in the lower 48, this is a spider you can reasonably expect in a garden.
Sunny gardens, tall grass, hedgerows and the edges of fields — anywhere with stems strong enough to anchor a big web.
Females reach full size in late summer, which is when people notice them.
How it behaves
It sits in the centre of the web day and night and rebuilds much of it each morning, eating the old silk. If disturbed it vibrates the whole web rapidly — a startling defence that makes it look bigger and blurs its outline. The zig-zag band is called a stabilimentum, and after decades of argument its purpose is still not settled; the leading explanations are that it warns birds away from flying through the web, or that it reflects ultraviolet in a way that attracts insects.
What a bite looks like
Very rarely bites. Where it does, the result is a small red mark and mild local swelling that clears within a day or so.
Comparable to a bee sting, without the lasting ache.
We identify, we don't diagnose. See a doctor for any bite that swells significantly or shows signs of infection.
A skin mark cannot confirm which animal caused it. Read the bug bite and sting guide for the limits and the symptoms that should end an online search.
You’ve found one indoors
Leave it. A garden spider in a vegetable patch is eating exactly the insects you do not want, and it will die naturally at the first hard frost. If the web is genuinely in the way, clear it in the evening and the spider will usually resite rather than rebuild in the same gap.
Common questions
What is the zig-zag in the web for?
It is called a stabilimentum and its function is genuinely unsettled. The two leading ideas are that it stops birds flying through the web, and that it reflects ultraviolet light in a way that draws insects in. Both may be true.
Is a writing spider dangerous?
No. 'Writing spider' is a regional name for this species, after the zig-zag. It is harmless and reluctant to bite.
Why does it shake its web when I get close?
It is a defence. Vibrating the web blurs its outline and makes it look larger and harder to grab. It is a bluff, not a prelude to anything.
Where does it go in winter?
It dies. Yellow garden spiders live a single season; the female lays egg sacs in autumn and the spiderlings emerge the following spring.
M. Whitson · CC-BY